The pH meter can only be used to differentiate between weak and strong acids providing that the concentrations are known. However, it is convenient to determine the concentration of an acid (or base) by titration.
Answer:
The reactivity of Group 7 elements decreases down the group. ... The electrons in the outer shell move further away from the nucleus as we go down the group and the attraction force between the electrons and the nucleus become weaker and weaker. This weaker attraction in the larger atoms makes it harder to gain electron.
Answer:
After 4 days 10 g will left
After 8 days 5 g will left.
Explanation:
Given data:
Half life of isotope = 4 days
Total amount of sample = 20 g
Amount left after each time period = ?
Solution:
The half life of radioactive isotope is 4 days it means after 4 days the amount left will be half of total amount.
20 g/2 = 10 g
The half amount which is left will be consume in next 4 days and remaining amount will be,
10 g/2 = 5 g
After 4 days 10 g will left
After 8 days 5 g will left.
